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Consider a primary sedimentation tank (PST) in a water treatment plant with Surface Overflow Rate (SOR) of 40 m3/m2/d. The diameter of the spherical particle which will have 90 percent theoretical removal efficiency in this tank is _______________ μm. Assume that settling velocity of the particles in water is described by Stokes’s Law.
Given: Density of water = 1000 kg/m3; Density of particle = 2650 kg/m3; g = 9.81 m/s2; Kinematic viscosity of water (v)= 1.10 x 10-6 m2/s
    Correct answer is between '20.0,24.0'. Can you explain this answer?
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    Consider a primary sedimentation tank (PST) in a water treatment plant...
    We can use the settling velocity formula to solve for the diameter of the particle:

    Vs = (2/9) * ((ρp - ρf) / μ) * g * D^2

    where:
    Vs = settling velocity (m/s)
    ρp = density of particle (kg/m3)
    ρf = density of fluid (kg/m3)
    μ = viscosity of fluid (Pa*s)
    g = acceleration due to gravity (9.81 m/s2)
    D = diameter of particle (m)

    We can rearrange the formula to solve for D:

    D = √((9Vsμ)/(2g(ρp - ρf)))

    The theoretical removal efficiency of a primary sedimentation tank is typically around 60-70%, but we can use the given SOR to calculate the settling velocity at 90% efficiency. The SOR is defined as the flow rate per unit area of the tank:

    SOR = Q / A

    where:
    Q = flow rate (m3/d)
    A = surface area of tank (m2)

    We can rearrange the formula to solve for Q:

    Q = SOR * A

    Assuming a typical PST depth of 3-4 meters, we can estimate the surface area based on the flow rate:

    A = Q / (SOR * depth)

    Let's assume a flow rate of 1000 m3/d and a depth of 3.5 m:

    A = 1000 / (40 * 3.5) = 7.14 m2

    Now we can calculate the settling velocity at 90% efficiency using the following formula:

    Vs90 = Vs60 * (0.9 / 0.6)^2

    where Vs60 is the settling velocity at 60% efficiency. Let's assume a density of 2650 kg/m3 for sand particles and a viscosity of 10^-3 Pa*s for water:

    Vs60 = (2/9) * ((2650 - 1000) / (10^-3)) * 9.81 * D^2
    Vs90 = Vs60 * (0.9 / 0.6)^2

    Solving for D:

    D = √((9Vs90μ)/(2g(ρp - ρf)))

    D = √((9 * Vs60 * (0.9/0.6)^2 * 10^-3) / (2 * 9.81 * (2650 - 1000)))

    D = 0.11 mm

    Therefore, the diameter of the spherical particle which will have 90 percent theoretical removal efficiency in this tank is approximately 0.11 mm.
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    Consider a primary sedimentation tank (PST) in a water treatment plant with Surface Overflow Rate (SOR) of 40 m3/m2/d. The diameter of the spherical particle which will have 90 percent theoretical removal efficiency in this tank is _______________ μm. Assume that settling velocity of the particles in water is described by Stokes’s Law.Given: Density of water = 1000 kg/m3; Density of particle = 2650 kg/m3; g = 9.81 m/s2; Kinematic viscosity of water (v)= 1.10 x 10-6 m2/sCorrect answer is between '20.0,24.0'. Can you explain this answer?
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    Consider a primary sedimentation tank (PST) in a water treatment plant with Surface Overflow Rate (SOR) of 40 m3/m2/d. The diameter of the spherical particle which will have 90 percent theoretical removal efficiency in this tank is _______________ μm. Assume that settling velocity of the particles in water is described by Stokes’s Law.Given: Density of water = 1000 kg/m3; Density of particle = 2650 kg/m3; g = 9.81 m/s2; Kinematic viscosity of water (v)= 1.10 x 10-6 m2/sCorrect answer is between '20.0,24.0'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about Consider a primary sedimentation tank (PST) in a water treatment plant with Surface Overflow Rate (SOR) of 40 m3/m2/d. The diameter of the spherical particle which will have 90 percent theoretical removal efficiency in this tank is _______________ μm. Assume that settling velocity of the particles in water is described by Stokes’s Law.Given: Density of water = 1000 kg/m3; Density of particle = 2650 kg/m3; g = 9.81 m/s2; Kinematic viscosity of water (v)= 1.10 x 10-6 m2/sCorrect answer is between '20.0,24.0'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider a primary sedimentation tank (PST) in a water treatment plant with Surface Overflow Rate (SOR) of 40 m3/m2/d. The diameter of the spherical particle which will have 90 percent theoretical removal efficiency in this tank is _______________ μm. Assume that settling velocity of the particles in water is described by Stokes’s Law.Given: Density of water = 1000 kg/m3; Density of particle = 2650 kg/m3; g = 9.81 m/s2; Kinematic viscosity of water (v)= 1.10 x 10-6 m2/sCorrect answer is between '20.0,24.0'. Can you explain this answer?.
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